1. Field of the Invention
This invention pertains to railroad cars, and more particularly to railway cars being converted to gondola-like cars for rotary dumping of bulk granular freight such as coal.
2. Description of the Prior Art
Railway cars are often provided with hoppers and dump doors in the floor structure thereof to aid in off loading cargo from the car. For example, the U.S. Pat. No. 3,595,175 issued to R. J. Austill, discloses a hopper box freight carrier adapted for transporting freight in granular form.
Gondola cars are railway car provided with a sealed bottom, and are unloaded by rotary dumping, i.e. dumping the freight by turning the car upside down.
The hoppers, dump doors, and associated door control systems of a hopper car are generally made of heavy steel components, and the multiple moving parts are expensive to manufacture require maintenance and adjustment. Repeated use of the car and the possibly corrosive nature of the lading may cause a deterioration in the load containing envelope of the car over time, necessitating replacement of part or all of the load containing envelope. Structures supporting the hopper components are also heavy. It is one of the objects of the subject invention to reduce the weight of a car by doing away with such structures.
It is possible to reduce maintenance problems of hopper cars by welding the dump door shut and employing rotary dumping to unload the car. However, in that case all of the hopper structures and related components are carried as unnecessary weight. The subject invention resolves that the problem by stripping the bottom of the hopper car of all hoppers and replacing it with a unitary lightweight structure.
None of the references of record describes or teaches the novel structure and method of the subject invention being described in greater detail hereinbelow.